Lately I am involved in composite powerboat design (40-60 ft) with focus on GRP structure and boat strength.
Since I am quite new to composite boats could you please help me with your experience and knowledge on how to define hull structure geometry for preliminary calculations according to ISO 12215-5.
I am aware that there needs to be at least three bulkheads (1. between engine room and living space; 2. collision bulkhead at bow; and 3. somewhere in between engine and collision bulkhead to shorten the unsupported span of longitudinals.
Lead by the big ship structure logic, I tried to look at structure in this way:
- longitudinals should be continuous along the boat length (for longitudinal structure system). Span between bulkheads should be taken as unsupported span. My question is whether should the longitudinals break at bulkheads, or should the bulkheads go over the longitudinals.
- is it ok to consider beam (longitudinal) fully supported if bulkeads goes over it, but bulkheads is glued to longitudinal with structure glue.
- can the plywood or grp sandwich cross-beam (partial bulkhead between hull and hull liner) be consider as a fully support to longitudinals if glued with structural glue and over-laminated to longitudinals?
Please, any other advice, recommendations and literature suggestions as well as principle sketches are very welcome and will be of great help.
Thank you a lot.
(my contact e-mail is firstname.lastname@example.org